In China short messaging services have become really popular. So far, 260 million cell phone users have sent 220 billion SMS messages. Even Chinese political organizations are using SMS to communicate with the public.
Here in the U.S. SMS is barely scratching the surface of mainstream communication. Nobody in my family uses it because it's not in our plan, and if it's not in your plan then you have to pay extra. It's about 10 to 20 cents per message, so it's not worth it. Hopefully SMS will be cheaper in the U.S. in the future.